22 degrees Celsius would be adequate as a NTL (night time low)
That temp will cycle BRB well enough to reproduce.
With a DTH (day time high)of 27 to 28 degrees Celsius.
You could use a hot spot to create the DTH and remove it to create the night time low.
I for one believe cycling improves the outcome of breeding success but is not essential to get a viable outcome breeding BRB's and many other Boids as well.
Most people cycle Ratsnakes to get a viable outcome. I have got eggs from a female Texas ratsnake cooking right now, not one clutch but two. (female double clutched 9 eggs then 30 days later 14 eggs) Now this may not be a Boid but it is an example of how cycling may not always be necessary to get a viable outcome when it comes to breeding snakes.
Although I have only bred BRB's twice in the past and I did cycle them to at least 75 to 84 degrees to achieve it. It would be safe to say I hit 70 degrees on a few occasions and as high as 86 a few times as well. When hot spot hit 85 the female BRB got as far away from it as was possible still staying in the high 70's low 80's as a body temp.
I have never seen the stuff till this year.



same day...

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Roberts Realm Of Reptile Research
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Thanks,
Frank Roberts

I opened my mouth and out flowed a melody black.